The present invention is related to a hand tool, and more particularly to a tool coupling device applicable to a splined wrench to provide ratchet effect.
FIG. 9 shows a conventional tool-coupling device. The tool-coupling device includes a connecting member 7 having a chucking section 71, a polygonal connecting section 72 and an arresting section 73. The connecting section 72 is formed with an annular chucking groove 74. A fast unplugging unit 75 is disposed at the center of the connecting member 7. The fast unplugging unit 75 serves to control a steel ball 76 to protrude from one side of the arresting section 73 or retract into the arresting section 73. A C-shaped retainer 8 is inlaid in the chucking groove 74. The retainer 8 is bent to form multiple engaging sections 82 and restricting sections 81.
When assembled with a splined wrench 6, the polygonal connecting section 72 is inserted in the splined hole 61 of the splined wrench 6. The chucking section 71 abuts against top face of the wall of the splined hole 61. The restricting sections 81 and engaging sections 82 of the retainer 8 abut against the wall faces of the connecting member 7 and the splined hole 61. Accordingly, the connecting member 7 is coupled with the splined wrench 6. A the connecting member 7 is coupled with the splined wrench 6. A socket can be fitted on the arresting section 73.
The above chucking device only provides a fixing effect. In use, the chucking device can be only one-way rotated. The rotational direction of the splined wrench cannot be changed. As a result, when the splined wrench is turned to a limit, it is necessary to take up the splined wrench and then re-wrench the work piece. This is quite inconvenient and troublesome to a user.